# 给定一个未排序的整数数组 nums ，找出数字连续的最长序列（不要求序列元素在原数组中连续）的长度。 
# 
#  请你设计并实现时间复杂度为 O(n) 的算法解决此问题。 
# 
#  
# 
#  示例 1： 
# 
#  
# 输入：nums = [100,4,200,1,3,2]
# 输出：4
# 解释：最长数字连续序列是 [1, 2, 3, 4]。它的长度为 4。 
# 
#  示例 2： 
# 
#  
# 输入：nums = [0,3,7,2,5,8,4,6,0,1]
# 输出：9
#  
# 
#  
# 
#  提示： 
# 
#  
#  0 <= nums.length <= 10⁵ 
#  -10⁹ <= nums[i] <= 10⁹ 
#  
# 
#  Related Topics 并查集 数组 哈希表 👍 2317 👎 0
from typing import List


# leetcode submit region begin(Prohibit modification and deletion)
class Solution:
    def longestConsecutive(self, nums: List[int]) -> int:
        if not nums:
            return 0
        set_nums = set(nums)
        maxlen = 0
        for n in set_nums:
            if n - 1 not in set_nums:
                # 找出连续的长度
                star = n
                length = 1
                while star+1 in set_nums:
                    star += 1
                    length += 1
                maxlen = max(maxlen, length)
        return maxlen


# leetcode submit region end(Prohibit modification and deletion)
print(Solution().longestConsecutive(nums=[0,3,7,2,5,8,4,6,0,1]))
